Differences in Brain Cell Nuclear DNA as Determined by Flow Cytometry

Abstract

Nuclei selected from various areas of normal brain tissue (rat, canine and man) were isolated by means of tissue grinding, stained with Acriflavin-Feulgen, and the amount of DNA in each individual nucleus was measured. It would appear that two distinct populations of diploid cells exist in the cerebral gray matter, either with regard to their absolute DNA content (approximately 10% more than the diploid amount) or with regard to their ability to be stained by Acriflavin-Feulgen. Microscopic examination of nuclei sorted from each population revealed that those which carried a "hyperdiploid" amount of DNA consisted primarily of nuclei with diameters of 12-16 ƒÊm in contrast to nuclei in the other peak with diameters of 6-8 ƒÊm. These results suggest that some neuronal nuclei in the cerebral gray matter, e.g. pyramidal and Betz cells, may contain a "hyperdiploid" amount of DNA as measured by FCM. The possible biological significance of this observation is not understood at this time.